TECHNOLOGY Preliminary assay reveals quality of Mars blend

Anne K. Rhodes
Refining/Petrochemical Editor

Mars Distillation Data [24000 bytes]

Shell Oil Co. has assayed a preproduction well sample of Mars blend, from the Louisiana Gulf of Mexico.

The assay shows the crude to have an API gravity of 31° and a sulfur content of 2.0 wt %. Distillation data for the crude are shown in Table 1. [24000 bytes]

When partners Shell (71.5%) and BP (28.5%) begin commercial production in July, several producing zones will be tapped through a number of wells. Shell says the final sales quality of Mars Blend may vary from the qualities of this representative sample.

The crude will be produced from a tension-leg platform (TLP) at a water depth of 2,940 ft (OGJ, Apr. 8, p. 23). The TLP is anchored in Mississippi Canyon Block 807, about 130 miles southwest of New Orleans (map).

MARS field will be the principal source of the crude initially. Shell says production will escalate to about 100,000 b/d crude and 110 MMcfd natural gas in 1997. Ultimate recovery is estimated to be 700 million BOE.

Distribution

The crude will be piped ashore to the Fourchon, La., area, where it will join the Amberjack pipeline (map). Shell says it will tie other fields with similar-quality crudes into the Mars/

Amberjack pipeline later. Ultimate capacity of the network is 500,000 b/d.

From Fourchon, the crude will be transported to a 3 million bbl salt dome cavern at Clovelly, La., operated by LOOP Inc. Gulf Coast and Midcontinent refiners can access the LOOP facility through a number of major pipelines.

Mars blend, Offshore Louisiana

Whole crude
Gravity, °API: 31.0
Sulfur, wt %: 2.0
Rvp @ 100° F, psia: 8.0
H2S, g/100 ml: 0.0011
Pour pt., °F.: -33
Total acid no., mg KOH/g: 0.45
Visc. @ 80° F., SSU: 82.8
Visc. @ 100° F., SSU: 64.2
Visc. @ 140° F., SSU: 45.9

Light ends
Range, °F.: IBP-68
Yield, vol %: 2.8
Iso-to-normal ratio: 0.30
Parrafins, vol %: 100.0
Naphthenes, vol %: 0.0
Aromatics, vol %: 0.0

Gasoline
Range, °F.: 68-155
Yield, vol %: 6.9
Gravity, °API: 85.1
Rvp @ 100° F., psia: 12.8
RON (calculated): 68.0
MON (calculated): 66.9
Sulfur, wt %: <0.02
Iso-to-normal ratio: 0.89
Paraffins, vol %: 92.0
Naphthenes, vol %: 7.3
Aromatics, vol %: 0.7

Light naphtha
Range, °F.: 155-265
Yield, vol %: 9.0
Gravity, °API: 62.9
Sulfur, wt %: <0.02
Nitrogen, ppm(wt): <1
Iso-to-normal ratio: 1.14
Paraffins, vol %: 62.6
Naphthenes, vol %: 32.3
Aromatics, vol %: 5.1

Heavy naphtha
Range, °F.: 265-350
Yield, vol %: 8.0
Gravity, °API: 52.4
Hydrogen, wt %: 14.25
Sulfur, wt %: 0.13
Nitrogen, ppm(wt): <1
Iso-to-normal ratio: 1.68
Total acid no., mg KOH/g: 0.00
Paraffins, vol %: 59.0
Naphthenes, vol %: 25.5
Aromatics, vol %: 15.5

Kerosine
Range, °F.: 350-500
Yield, vol %: 12.9
Gravity, °API: 42.8
Cetane index: 47.0
Hydrogen, wt %: 13.74
Sulfur, wt %: 0.49
Mercaptan S, wt %: 0.0010
Nitrogen, ppm(wt): <1
Basic N, ppm (wt): 2
Smoke pt, mm: 21
Freeze pt., °F.: -49.6
Pour pt., °F.: -66
FIA aromatics, vol %: 21.3
UV diaromatics, vol %: 2.1
UV monoaromatics, wt %: 8.26
UV diaromatics, wt %: 2.92
UV triaromatics, wt %: 0.20
UV tetra-aromatics, wt %: 0.00
UV total aromatics, wt %: 11.23
Refractive index @ 20° C.: 1.4516
Total acid no., mg KOH/g: 0.04

Heavy gas oil
Range, °F.: 350-500
Yield, vol %: 12.7
Gravity, °API: 32.6
Cetane index: 48.1
Hydrogen, wt %: 12.94
Sulfur, wt %: 1.28
Mercaptan S, wt %: 0.0010
Nitrogen, ppm(wt): 44
Basic N, ppm (wt): 30
Pour pt., °F.: 0
UV monoaromatics, wt %: 5.49
UV diaromatics, wt %: 5.60
UV triaromatics, wt %: 1.28
UV tetra-aromatics, wt %: 0.56
UV total aromatics, wt %: 12.93
Refractive index @ 20° C.: 1.4793
Total acid no., mg KOH/g: 0.24

FCC feed
Range, °F.: 650-1,000
Yield, vol %: 24.6
Gravity, °API: 21.8
Hydrogen, wt %: 12.15
Sulfur, wt %: 2.13
Nitrogen, ppm(wt): 953
Basic N, ppm (wt): 280
UV monoaromatics, wt %: 4.82
UV diaromatics, wt %: 3.30
UV triaromatics, wt %: 3.79
UV tetra-aromatics, wt %: 2.42
UV total aromatics, wt %: 14.31
Total acid no., mg KOH/g: 0.32
Conradson C, wt %: 0.20
Ramsbottom C, wt %: 0.29
Visc. @ 140° F., SSU: 117.1
Visc. @ 210° F., SSU: 50.3

Long residue
Range, °F.: 650+
Yield, vol %: 47.7
Gravity, °API: 14.3
Hydrogen, wt %: 11.24
Sulfur, wt %: 3.24
Nitrogen, ppm(wt): 2,986
Basic N, ppm (wt): 826
UV monoaromatics, wt %: 5.50
UV diaromatics, wt %: 3.65
UV triaromatics, wt %: 4.81
UV tetra-aromatics, wt %: 6.34
UV total aromatics, wt %: 20.30
Fe/Cu/Na ppm(wt): 0/0/7
V/Ni, ppm(wt): 84/34
Total acid no., mg KOH/g: 0.34
Conradson C, wt %: 9.30
Ramsbottom C, wt %: 7.10
Visc. @ 210° F., SSU: 316.1

Pitch
Range, °F.: 1,000+
Yield, vol %: 23.1
Gravity, °API: 4.7
Sulfur, wt %: 4.38
Basic N, ppm (wt): 1,476
UV monoaromatics, wt %: 6.00
UV diaromatics, wt %: 3.79
UV triaromatics, wt %: 5.67
UV tetra-aromatics, wt %: 10.25
UV total aromatics, wt %: 25.72
Fe/Cu/Na, ppm(wt): 0/1/13
V/Ni, ppm(wt): 168/66
Total acid no., mg KOH/g: 0.23
Conradson C, wt %: 18.70
Abs. visc. @ 140° F., poise: 1,430.0
Kin. visc. @ 275° F., cSt: 348.8
Penetration @ 77° F., dmm: 76